The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 18, 1986
Filed:
Mar. 04, 1985
Donald R Weir, Fort Saskatchewan, CA;
Roman M Genik-Sas-Berezowsky, Edmonton, CA;
Sherritt Gordon Mines Limited, Toronto, CA;
Abstract
A process for recovering gold from refractory auriferous iron-containing sulphidic ore which comprises feeding ground ore as an aqueous slurry to an acidic pretreatment step. The ground ore in the acidic pretreatment step is treated with aqueous sulphuric acid solution to decompose carbonate and acid consuming gangue compounds, and subjecting the treated slurry to a first liquid-solids separation step to produce a sulphate solution and separated solids. Water is added to the separated solids in a first repulping step to form a slurry having a pulp density in the range of from about 25 to about 60% by weight solids. The first repulped slurry is oxidized in a pressure oxidation step at a temperature in the range of from about 135.degree. to about 250.degree. C. under a pressurized oxidizing atmosphere while maintaining a free acid concentration of from about 5 to 40 g/L sulphuric acid to cause dissolution of iron, formation of sulphuric acid and oxidation of substantially all oxidizable sulphide compounds to sulphate form with less than about 20% of oxidized sulphur being present as elemental sulphur during the oxidation step. Water is added to the oxidized slurry in a seocnd repulping step to produce a repulped oxidized slurry with a pulp density in the range of from about 5 to 15% by weight, and subjecting the repulped oxidized slurry to a second liquid-solids separation step to produce an acid and iron containing solution and oxidized separated solids. The acid and iron containing solution is recycled to at least one of the first and second repulping steps.